The Prophet (may Allah’s peace and blessings be upon him) performed ablution by washing the body parts once
Ibn ‘Abbās (may Allah be pleased with him) reported:
The Prophet (may Allah’s peace and blessings be upon him) performed ablution by washing the body parts once.
تَوَضَّأَ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَرَّةً مَرَّةً.
When the Prophet (may Allah's peace and blessings be upon him) performed ablution, he would sometimes wash each organ of the organs of ablution once - washing the face - including rinsing the mouth and sniffing water into the nostrils - and the hands and feet once. This is the due amount.
...:
It is obligatory to wash the body parts of ablution once. However, exceeding that is recommended.
It is permissible to sometimes wash the body parts of ablution once.
Wiping over the head once is prescribed in the sunnah.
Sahīh Al-Bukhāri (1/ 43) (157).
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إرشاد الساري لشرح صحيح البخاري (1/ 244).